REPORT ON THE RADIOLARIA. 845 



5. Icosaspis spectahiUs, n. sp. 



Parmal meshes very different ; in the centre of each plate four very large, pentagonal aspinal 

 pores, and around these two to three circles of smaller polygonal coronal pores, which are very 

 numerous, and not larger than the small sutural pores. Eadial spines quadrangular, prismatic, 

 stout, very long ; the outer part two to three times as long as the inner. 



I)i'm.c7isio7is. — Diameter of the shell 0'4, of the larger aspinal meshes 0'03, of the outer meshes 

 0-002 to 0-02, bars 0-005. 



Habitat. — South Atlantic, Station 333, surface. 



6. Icosasjjis multiforis, n. sp. 



Parmal me.shes very numerous, more than one hundred in each jjlate ; in the centre four larger 

 pear-shaped pores, and around these four to five circles of smaller pores, becoming gradually smaller 

 towards the margin of the plate ; the sutural meshes also very small and numerous (more than fifty 

 around each plate), so that the number of all the pores together amounts to two thousand or even 

 more. Kadial spines thin, cylindrical, very long. 



Dimensions. — Diameter of the shell 0-32 ; larger aspinal pores 0-02, smaller 0-002 to O'Ol ; 

 bars 0-003. 



JTaMtat. — Indian Ocean (Madagascar), Piabbe, surface. 



Subgenus 2. Icosaspidium, Haeckel. 



Definition. — Condyles of the neighbouring j)lates gro-wn together, and sutures 

 obliterated ; therefore the -R-liole shell forms a single piece of acanthin. 



7. Icosaspis tetragon opa, Haeckel. 



Haliommatidlum tetragonoimm, Haeckel, 1862, Monogr. d. Radiol., p. 421, Taf. xxii. fig. 13. 



Parmal meshes all of nearly equal size and form, square, three times as broad as the bars, little 

 larger than the sutural meshes. In each plate commonly sixteen equal square meshes, viz., four 

 primary aspinal and twelve secondary, surrounding the former as a square corona. Eadial spines 

 tetrapterous, stout ; the outer pyramidal half somewhat longer than the inner. This species differs 

 from the similar Icosaspis tahulata (PL 136, fig. 2) in the concrescence of the sutures, the smaller 

 number of pores, and the form of the stouter spines. The figure in my Monograph, drawn from a 

 broken fragment, is not quite correct. 



Dimensions. — Diameter of the shell O'lS, pores O'OOO, bars O'OOS. 



Habitat. — Mediten-anean (Messina, Corfu), surface. 



8. Icosaspis icosahedra, n. sp. 



Parmal meshes of different size and form ; in the centre of each plate a cross of four pentagonal, 

 primary aspinal pores, surrounded by a complete corona of twelve to sixteen polygonal coronal 



